This function returns an object indicating the success or failure of the
operation.  Valid values to be returned are:

\begin{itemize}[noitemsep]
\item The returned object, represented as a map from attributes' names to Java
    objects.
\item \code{False} if any provided predicates failed.
\item \code{null} if the operation requires an existing value and none exists
\end{itemize}

On error, this function will raise a \code{HyperDexClientException} describing
the error.
